The same aperture gives a completely different depth of field on a full frame body than it does on a phone, this works out exactly how much is actually sharp, for your specific gear.
Free camera tool
Depth of Field Calculator
See exactly how much of your shot will be in focus, near limit, far limit, and the hyperfocal distance, for any sensor, lens and aperture.
Runs entirely in your browser. Nothing you enter is sent anywhere.
Why the "circle of confusion" matters
A point that isn't perfectly in focus doesn't render as a point, it renders as a small blurred disc, the circle of confusion. As long as that disc is smaller than what your eye can resolve at a normal viewing distance, it still reads as "sharp." This calculator uses the sensor's diagonal ÷ 1500 to estimate that threshold, the convention most online depth of field calculators default to. It's an estimate of human perception, not a hard physical line, so treat the near and far limits here as a reliable guide rather than a millimeter-exact cutoff.
Depth of field calculator FAQ
What exactly is "depth of field"?
It's the zone in front of and behind your focus point that still looks acceptably sharp. Everything outside that zone blurs progressively, there's no hard edge, the near and far limits shown here mark where the blur becomes noticeable rather than a sudden cutoff.
How does aperture change depth of field?
A smaller aperture (a larger f-number, like f/16) gives more depth of field, a larger aperture (a smaller f-number, like f/1.8) gives less. This is the main reason portrait shooters open up wide to blur the background, and landscape shooters stop down to keep the whole scene sharp.
Why does depth of field depend on sensor size?
A smaller sensor needs a shorter focal length to get the same framing as a larger one, and shorter focal lengths inherently produce more depth of field at a given aperture. So two cameras with different sensor sizes framed identically, at the same f-number, won't actually have the same depth of field, the smaller sensor will have more.
What's the difference between this and the hyperfocal distance calculator?
This tool answers "if I focus on my subject at this distance, what's sharp?" The hyperfocal distance calculator flips the question around: "where should I focus to get everything from some near point out to infinity sharp?" Landscape photographers often want the second question, this one is more general-purpose.
Is the circle of confusion value exact?
No, it's a working estimate of what a person can perceive as sharp, not a hard optical boundary. This calculator uses each sensor's diagonal divided by 1500, the convention most online depth of field calculators default to. Different sources use slightly different divisors, so treat the near and far limits as a reliable guide rather than a millimeter-exact line.
Free depth of field calculator by ANUPRESS
The aperture number lies without the rest of the story
“f/2.8 is shallow, f/11 is deep” is true as a direction but useless as a number, since the same f-stop produces a different depth of field depending on focal length, sensor size, and how far you are from the subject. A macro shot at f/11 can have paper-thin focus, a landscape at f/2.8 on a wide lens from ten meters away can hold most of the frame sharp. The aperture is one input among four, not the answer by itself.
Sensor size changes the math, not just the crop
Framing a subject identically on two different sensor sizes means using two different focal lengths, and shorter focal lengths inherently produce more depth of field at a given aperture. That’s the real reason phone photos look deep-focus by default and full-frame portraits blur backgrounds so easily, it isn’t really about the aperture number at all, it’s downstream of the much shorter focal length a small sensor needs to get the same shot.
One number tells you where to focus for maximum sharpness
The hyperfocal distance is the closest you can focus while still keeping infinity acceptably sharp, useful the moment a shot needs both a close foreground and a distant background in focus at once, the classic landscape problem. Focus any closer than that number and the horizon starts to soften, focus there and you get the widest possible sharp range the lens and aperture can produce.